Latch formed by superimposed sheets



y 1, 1956 e. w. POPPE LATCH FORMED BY SUPERIMPOSED SHEETS Filed Feb. 1,1954 INVENTOR. 6500s: it. flop/ 5 BI Ilia/7m,

ATTORNEYS.

LATCH FORMED BY SUPERIMPO'SED SHEETS George W. Poppe, Stroudsburg, Pa.,assignor to Equitable Paper Bag Co. Inc., Long Island City, N. Y., acorporation of New York Application February 1, 1954, Serial No. 407,2314 Claims. c1. 229-77 This invention relates to a latch formed bysuperimposed sheets of flexible material. The invention is particularlyadapted for incorporation in a paper bag, envelope or the like, in whichcase the superimposed sheets are provided by the parts of the articlewhich are fastened together by the latch. For example, one wall of a bagor envelope may be extended to form a flap which folds down over theother wall, in which case the flap would provide one of the superimposedsheets while the other would be provided by the two walls of the bagwhich would function cooperatively.

One of the objects is to provide a latch construction which is suitablefor application to paper bags, envelopes and the like, which may becreated only by forming appropriately contoured lines of severancethrough the parts to be fastened together, and which provides an easilymanipulated latch. Another object is to provide such a latch in a formthat will have an attractive appearance. Other objects may be inferredfrom the following disclosure of specific examples of the invention.

These examples are illustrated by the accompanying drawings in which:

Fig. 1 is a perspective view showing a preferred form of the inventionas incorporated in a paper bag or envelope having a flap fastened closedby the new latch;

Fig. 2 shows the top portion of Fig. 1 as the construction appears priorto latching and with the flap fully opened;

Fig. 3 is a cross section taken on the line 3-3 in Fig. 1;

Fig. 4 shows the upper portion of a bag or envelope having a fiap closedby a modification of the invention; and

Fig. 5 shows the construction of Fig. 4 as it appears when the flap isopened and prior to engagement of the new latch construction.

In the form shown by Fig. 1 the bag or envelope has a front wall 1 and aback wall 2, the back wall being extended to form a flap 3 which may befolded down over the front wall 1. All of the parts of this article areformed from sheet material such as paper or the like. This material hasa certain amount of elasticity and stiffness when it is not bentexcessively. The constructional details of the bag or envelope, such asthe manner in which it is folded from sheet material, seamed, bottomed,and similar details, is unimportant insofar as the present invention isconcerned.

The two walls 1 and 2 may be considered as a single sheet, the flap 3constituting a second sheet, these sheets being superimposed when theflap is folded downwardly.

According to the invention, the walls 1 and 2 have an nited StatesPatent the curve 6 is formed so that when the flap 3 is closed, orfolded downwardly, the curves 4 and 6 curve in the same direction. Also,the central portions 5 and 7 of the respective curves mutually registerwhen the flap is closed. However, the curves 4 and 6 have differentdegrees of curvature respectively and, therefore, the curved lines ofseverance respectively diverge from each other in both directions fromtheir central portions to their opposite end portions. This results inthe mutually adjacent ends of the two curves being offset from eachother transversely with respect to the bag or envelope.

The line of lesser curvature, which is the line of severance 4 in thedrawings, has a return portion 8 which extends back to the line ofgreater curvature, which is the line 6 in the drawings, at each of theend portions of the line of severance 4. The line of severance ofgreater curvature 6 defines oppositely pointing tabs 9 which may beelastically displaced to form openings 10, and the line of lessercurvature 4 defines oppositely pointing tabs 11 having shoulders 12,defined by the return portions 8, and which may be pushed through theopenings 10 by elastic displacement of the shoulders 12. This action .iscarried out when the sheets are superimposed and ready to be fastenedtogether, and the action may be effected simply by pushing the tabs 11towards the tabs 9.

1 It is to be noted that the tabs have mutually registered S-curved lineof severance 4 formed therethrough and this modified latch construction.

hinging base lines, indicated by the broken line 1313 in the drawings,these hinging base lines extending straight between the end and centralportions of the lines of severance 4 and 6, in each instance.

. The line of greater curvature 6 continuously curves reversely betweenits end portions. It may take the form of two semi-circles joined toform an S-curve. The line of lesser curvature 4 has its previouslymentioned return portions 8 extending back to the line of greatercurvature 6, when the sheets are superimposed, at both ends thereofsubstantially straight and in alignment with the base lines indicated bythe broken line 1313. Excepting for these return portions, the line 4also continuously curves reversely between its end portions, the desiredS-curve in this instance being also formed by two appropriately joinedsemi-circular lines of severance.

In the modification shown by Figs. 4 and 5 a half S-curve latchconstruction is provided. Thus the line 4a is only a semi-circle, oneend of this line representing the central portion 5a of the S-curve. Thecurve 6a carries along this idea, and it is to be noted that the curve4a has thereturn portion 8a of the full S-curve. The main difference isthat the latching action only occurs when the flap is pulled straightaway from the walls of the receptacle, or at an angle directed towardsthe latters center. A pull on the flap directed away from the centralportion of the bag or envelope might unlatch Therefore, when thismodified construction is used it is preferable to incorporate bothhalves of the previously described S-curve construction.

As is shown by Figs. 4 and 5 the two halves of the S-curve constructionmay be changed so that the tabs provided both point upwardly. This isnot necessary but it does provide a better appearance. However, it isquite preferable to arrange the two half S-curve constructions so thatthe shoulders 12a point in opposite directions transversely to the bagor envelope. By doing this a secure latching elfect is obtained becausethe two latch constructions best resist unlatching in oppositedirections and, therefore, mutually cooperate to fasten the flap closedin a secure manner regardless of the direction of force supplied to openthe flap.

In the modified form the parts which correspond to those of the fullS-curve form are given similar numerals in conjunction with the lettera. The mode of operation is similar in both cases but the full S-curveconstruction provides the maximum security in all instances.

This new latch construction has the great practical advantage that oneof the tabs, providing the latch shoulder, may be made considerabl-ywider than the hole through which it is pushed by displacement of thecorresponding tab of the other sheet. The curved shapes permit theshoulder to elastically deform and to then snap behind the other sheetafter the shouldered tab is pushed through the opening. In the case ofthe full S-curve construction the shouldered tabs may be madeconsiderably wider than the openings through which they are pushed. Thisadvantageous feature cannot be provided so effectively by prior artconstructions because in the latter it is very easy to tear the paper orother material when causing locking action of the locking tabs.Anotheradvantage of the present invention is the obviouslyattractive-appearance that results from its use. The construction isinexpensive because it may be produced merely by die cutting the sheetsto provide the appropriate curves disclosed hereinabove.

I claim:

1. A latch for abag having a front and back walls and a flap. connectingwith one of said. walls and folded down over the other of said walls,said walls and flap being made of elastically flexible material and saidwalls together forming one sheet and said flap being superimposedthereonand forming another sheet, said sheets having linesof severance formedtherethrough respectively, all of said lines being curved in the samedirection :and having different degrees of curvature respectively, allof said lines-extending between interspaced locations and all of said.lines: being mutually registered substantially-at one of said locationsand respectively diverging from each other while e-xtcndiugtosthe otherofsaid locations and at the latter location the lineoflessercurvaturelhaving a re-l turn portion extending back to the lineof greatercurvature, the latter line defining a tab which maybedisplaced to form an, opening and said line of lesser curvature defininga tab having a, shoulder,.defined bysaid return portion of this line,and, which may be pushed through .saidopening y las ic pla ement of saidshoulder, the latter latching wi h the one f sai heet iuwh ebsaidopening isformed h n p s e ue said open ng.

2.. A lat h f r h s ha inat cr t. and back Walls'and a p c ing- W t 9 16at saidwalls and. toldecldown ver he other f i w lls. Said-Wall encl anbei made. of elastically fleXible m ltrial and said, walls to.- ehsrterm ngn sheetand said flap being superirrn pe edthereon anforming-an th r s eet, sai sheet having lines f,- e r nce f rmedthsethmnshresp ctively. all, of sai 'lines ei gcur ed in tbe same dir cti nand having different degrees .ofcurvature, respectively all of saidlines extending between interspaced locations, and all of saidline eingmu a y gi tere substanti l y at one. of said locations, andrespectively-diverging frorn eaeh other while, extending to. the otherof said locations. and at the l tter location e'line or les er c at re hving a return portion extending back to the lineof greater urva u he latr line d fining a b W ich aybe displaced to form an opening and saidline of lesser curvature defining a tab having a shoulder, defined bysaid return portion of this line, and which may be pushed through saidopening by elastic displacement of said shoulder, the latter latchingwith the one of said sheets 1n which said opening is formed when pushedthrough said opening, said tabs having mutually registered hing ing baselines extending straight frorn onfi. Of said loca H to h her in each nsance, sa d li f gre ter rv u on nu usly tm'rv rig ron me f sa dos afiapconnecting with one of said Walls and folded down over the other ofsaid Walls, said walls and flap being made ofelastically ,fiexiblematerial and said walls together forming one sheetand said flap beingsuperimposed thereon and forming another sheet, said sheets having linesof severance formed therethrough respectively, all of said lines bein gS-curved in the same direction but having different degrees of curvature, respectively, all of said lines having central portions which aremutually registered substantially and said lines respectively divergingfrom each other in both directions from said central portions to theiropposite end portions, the line of lesser curvature having-a returnportion extending back to said line of greate-rcurvature at each of itssaid end portions, said line of greater curvature definingoppositely-pointing tabs which maybe displaced to form openings and saidline I of; lessercurvature defining oppositely pointing tabs havingshoulders, definedbysaidreturn portions of this line, and whichlrnaybepushedthrough said openings by elastic displacementof said shoulders,the latter latching-with the one .ofsaid sheets in which said openingsare formed when pushed through said openings. 1

. .4. A latch for albag having from. and back walls and aflap-conneetingwith .oneof said walls and folded down oventhe Other ofsaid walls, said walls and vflapbeing ma e. .Ofelastically:.fiexiblematerial and said. walls to getheIiorr-ningonesheet and saidfiap being superimposed thereon and forming anotherlsheet,saidsheets having lines of severance. tanned therethreugh respectively,all of said lines-beings curved in. the same direction but havingdifierent degreesofj curvature respectively, .all of said lineshavingqeutral portions, which are mutually registered substantially andsaid lines respectively diverging from each Otherin, bqth glireotionsfrom said central portions to thei OBPQSitQ end pt rti usr the line. oflesser curvature having a rn-Parties xtending back to, ai line or sreterle ve llr at. each ef. i s and en portion said iasr st s Ql W 'L Iefining pp sitel pointing tabs which may be displaced to form openingsand said line Oi a r cur tur de n n pp sitely PQ ng t b havin shoulders,defined by said return portions of this line, and .1, 2 p l he -throughsaid openings, ,by elastic F p tssm m i ai s ultle e h atter t i w ththe one of said sheets in which said openings are formed wheupushedthrough said openings, said tabs havin mutually registered .hingi lg bse lines extending straight between all of their said portionsineachinstance, said line pi, greater. curvature; continuously curvingreversely between its saidend portions and said line of lessercurvature-having its, saidretur'n portions extending back to said 1mfigie etqurvature at both ends thereof substantially straighrand jnalignrnentwith said base lines, to define sa d tab andotherwi econtinuously u ing ,r v ely w n said a d p io s,

Referenges ,Cjtedin the file Qfihis patent UNFEED STATES PATENTS 229,893Kehr July 13, 1880 1,310,288 Nico; 'July'15, 1919 1,665,035 7Kleebaueret al Apr. 3, 1928 ,ZJIOQAH Poppe July 30, 1935 2,132,669 WolfOct. 11, 1938 52,536,384 Meller Jan. 2, 1951

